JP2001086925A - Instant dispatch of fish - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of prolonging the time to the postmortem rigidity of a fish and prolonging the quality keeping time. SOLUTION: Only the function of the spinal cord of a fish is stopped and the fish is then allowed to stand in water for >=5 min. The medulla elongata or dorsal aorta or both the medulla elongata and dorsal aorta are cut to carry out the instant dispatch of the fish. Only the spinal cord of the fish is cut without cutting the vertebrae and the dorsal aorta to thereby stop only the function of the spinal cord of the fish.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preserving live fish for a long time. More specifically, the present invention relates to techniques for extending the survival time of live fish tissue and techniques for delaying postmortem stiffness and associated biochemical changes.

[0002]

2. Description of the Related Art Fresh fish is a food material whose quality deteriorates very quickly. Various techniques have been devised in order to prevent quality deterioration and keep the product fresher. One of the causes of muscle quality deterioration is stiffness after death. Energy in muscle is stored in a substance called adenosine triphosphate (ATP). When the ATP stored in the muscle is used up, the muscle cannot exercise and stiffness occurs after death. Postmortem stiffness is accompanied by a decrease in pH and a flesh-white turbidity, leading to lower prices on the market. Therefore, maintaining ATP is very important for maintaining quality. One of the techniques for maintaining ATP is a technique called "vibrating". A typical method of "vibrating" is a method called medullary puncture. According to this method, the medulla is cut immediately after landing, thereby stopping the movement of the whole body and preventing the fish from writhing and minimizing the energy consumption in the muscle due to writhing. In addition, in order to prevent components in the blood from accelerating the deterioration of muscles or impairing the appearance at the time of vibrating, it is also common to cut blood vessels and allow blood to flow out.

[0003]

However, by virtue of vibrating the medulla by sacrifice of the medulla, writhing after cutting the medulla can be prevented,
The agony of scooping up and piercing the blade cannot be prevented. Also, ATP is basically not regenerated except for a small amount of regeneration from supplements such as creatine phosphate, since tissue mortality occurs shortly after the medulla is cut. Therefore, there is a limit in maintaining the quality by medullary stabbing. For example, in order to deliver fish that have been harvested at a landing site to a distant consumption site, a method that can delay stiffness after death for a longer time has been desired.

[0004]

As described above, the medulla oblongata must be cut in order to prevent the fish from writhing in the vigor, but ATP cannot be regenerated because the tissue dies.
In order to resolve the contradiction, it is necessary to have a technique for keeping the tissue alive for a longer period of time while stopping exercise. The present inventors have conducted intensive studies on the nerve cutting position and found that by cutting the spinal cord not in the medulla but in the part close to the medulla, it is possible to suppress the movement of muscles behind the gills, that is, the part that is generally consumed. The present invention has been completed. In this position, functions related to breathing and blood circulation do not stop, so that muscle tissue does not die immediately, as long as the vertebra and the blood vessels located on the ventral side of the vertebra are not damaged,
Since ATP is regenerated as long as the tissue is alive, the time until the disappearance of ATP and, consequently, the time until stiffness after death can be greatly increased.

[0005] Accordingly, the gist of the present invention is a method for keeping a fish alive, which stops only the function of the spinal cord of the fish. Also,
The gist of the invention of the present application is a method of vibrating a fish in which only the spinal cord function of a fish is stopped and then left in water for 5 minutes or more, and then the medullary or dorsal aorta or both the medullary and dorsal aorta are stopped. Furthermore, the gist of the present invention is a fish vibrating method in which only the spinal cord function of a fish is stopped by cutting only the spinal cord of the fish and not cutting the vertebrae and dorsal aorta. In addition, the present invention has a gist of a method of embedding a fish in which the functions of both the medullary or dorsal aorta or both medullary and dorsal aorta are stopped by cutting the medullary or dorsal aorta or both medullary and dorsal aorta. The gist of the invention of the present application is a fish vibrating method in which the spinal cord is cut at one place between the first vertebra and the fifth vertebra.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method for stopping the function of the spinal cord is to physically cut or destroy the spinal cord,
Although any method may be used, one of the cheapest and safest methods is amputation of the spinal cord. The method of stopping the function of the medullary or dorsal aorta or both medullary and dorsal aorta is similar, the method of cutting is the cheapest,
Safe and easy. The spinal cord can be cut by inserting an instrument such as a thin blade near the dorsal end of the gill hole or near the caudal side line of the gill lid. Since the spinal cord runs along the vertebra along the vertebrae, it is possible to cut only the spinal cord by first applying a cutting edge inserted into the vertebrae and sliding it along the vertebrae in the dorsal direction. Since the vertebra is harder than the spinal cord, it is possible to cut only the spinal cord without cutting the vertebra. At this time, there is no problem that a small scratch is made on the vertebra. In addition, since the blood vessels run on the ventral side of the vertebra, moving the instrument from the vertebra to the back does not damage the dorsal aorta. Note that the type of instrument, the insertion method, the instrument used for cutting, and the like are not limited to the above.

[0007] After the spinal cord is cut, it is fried and stored.
Tissues gradually die due to a loss of oxygen supply from the gills. Even in this state, the consumption of ATP is slow because the muscles do not agonize, but to keep the tissue alive longer, it is possible to keep the tissue alive longer by holding it in water after spinal cord transection. Also, to ship as live fish, transfer to the aquarium after spinal cord cutting, hold in water, and perform normal medullary stabbing, then stop the whole body movement as in normal medullary stabbing. Can be shipped. Since there is no ability to exercise muscles already, medullar puncture can be easily performed, and ATP consumption due to rampage does not occur, so that the quality retention time can be longer than when medullar puncture is performed from the beginning. In addition, it is also possible to cut blood vessels and discharge blood at the time of medullar puncture in the same manner as in normal vitalization.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments. The present invention is not limited by these examples.

Example 1 Six cultured red sea bream (average body weight: 1.5 kg) were scooped up from a fish cage with a hand net, and a blade with a width of about 5 mm was inserted from the vicinity of the side line on the caudal side of three gill holes. The spinal cord was cut near the area between the vertebra and the third vertebra (test section). The remaining three tails
A kitchen knife was inserted through the gill hole, and the medulla oblongata was cut off (control).
Both sections were fried from the water and stored in a refrigerator at 4 ° C, and the stiffness and ATP content were measured once every 2 to 4 hours after death. Postmortem rigidity was measured according to the method of Bito et al. That is, as shown in Fig. 1, the head of the fish is placed on a horizontal table, the tail side is hung from the corner of the table, and the sag immediately after cutting the spinal cord or medulla oblongata (R
0) and the sag (Rt) at each measurement time were measured and calculated by the following formula. Postmortem stiffness (%) = 100 x (R0-Rt) / R0 ATP amount is about 1 g of the normal muscle slightly behind the gill of each test fish.
Cut, homogenize in 10% perchloric acid (PCA) solution, centrifuge at 3000g, neutralize the supernatant with 10N or 1N potassium hydroxide solution, make volume in a volumetric flask, and perform high performance liquid chromatography. (HPLC). The extraction operation was performed under ice cooling, and the neutralized solution was stored at -80 ° C until analysis. HP
The LC analysis conditions are as follows: Eluent: Solution A: 0.2 M triethylamine-acetic acid (pH 6.6) Solution B: 0.2 M triethylamine-acetic acid (pH 6.6) -5% (v /
v) Acetonitrile 4% solution A: Starting with 96% solution B, 0% solution A: solution B in 25 minutes after 5 minutes
A linear gradient of 100% was used. Flow rate: 1.0ml / min Column: YMC-Pack ODS-AM 150mm × 6.0ID Column temperature: 40 ° C Detection: UV (260nm) Injection volume: 20μl

FIG. 2 shows the results of the post-mortem rigidity measurement. The progress of stiffness after death in the test plot progressed about 2 hours later than in the control plot. Regarding the amount of ATP, the control group had almost completely disappeared after 8 hours, but the ATP still remained in the test group and almost disappeared after 21 hours (FIG. 3). From the above results, it was shown that the quality-retention time was longer in spinal cord-cut fish than in normal medulla.

Example 2 Five cultured red sea bream (average body weight: 1.5 kg) were scooped up from a fish cage with a hand net, and a blade with a width of about 5 mm was inserted from the vicinity of the side line on the caudal side of two gill holes. The spinal cord was cut near between the vertebra and the third vertebra. Seawater was placed in a styrofoam box and stored in a refrigerator (4 ° C.) with ventilation. twenty four
After an hour, the medulla was scooped up and the medulla oblongata was cut with a kitchen knife (test section). For comparison, three red sea bream of the same size were scooped up from a fish cage with a hand net, a kitchen knife was inserted through the gill hole, and the medulla oblongata was cut off (control). Both sections were fried from the water and stored in a refrigerator at 4 ° C, and the stiffness and ATP content were measured once every 2 to 4 hours after death. The method described in Example 1 was used for analysis of postmortem stiffness and ATP. The results of postmortem rigidity measurements are shown in FIG. 12 controls
After about hours, the specimen had reached almost complete rigidity, whereas the test section approached complete rigidity 21 hours later. Regarding the amount of ATP (Fig. 5), the control group had almost disappeared to a trace after 8 hours, but the test group still had ATP remaining.
Almost disappeared after 21 hours. From the above results,
Spinal cord-dissected fish are kept in the same state as swimming in a fish cage while being left in the water for 24 hours. Time was shown to be extended.

[0012]

By using the method of the present invention, the time until stiffness after death can be extended, and the distribution of live fish products for a longer period of time becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for measuring post-mortem rigidity.

FIG. 2 is a view showing a change in rigidity after death during storage.

FIG. 3 is a graph showing a change in ATP content during storage.

FIG. 4 is a view showing a change in rigidity after death during storage.

FIG. 5 is a graph showing a change in ATP content during storage.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazuma Uematsu 1-4-4 Kagamiyama, Higashihiroshima City, Hiroshima Pref. Hiroshima University Faculty of Bioproduction F-term (reference)

Claims (5)

[Claims] 1. A method for keeping a fish alive, wherein only the function of the spinal cord of the fish is stopped. 2. After stopping only the spinal cord function of the fish, 5
A viable method of fish that stops functioning of the medullary or dorsal aorta or both medullary and dorsal aorta after standing in water for more than a minute. 3. The method according to claim 1, wherein only the function of the spinal cord of the fish is stopped by cutting only the spinal cord of the fish and not cutting the vertebrae and the dorsal aorta. 4. The method according to claim 2, wherein the medullary or dorsal aorta or both the medullary and dorsal aorta are cut off to stop the function of the medullary or dorsal aorta or both the medullary and dorsal aorta.
Or any one of the four methods for keeping fish alive. 5. The method according to claim 5, wherein the spinal cord is located between the first vertebra and the fifth vertebra.
The method according to claim 3 or 4, wherein the fish is cut at a location.